Block switching transient minimization for linear motors and inductive loads
AssigneeElectro Standards Laboratories
InventorRaymond B. Sepe, Jr.
Life of this patent
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Abstract
A block switch controller for a linear motor is disclosed, the block switch controller having a motor current threshold profile controlling the switching of a plurality of block switches in a linear motor. Also, a block switch controller for a linear motor comprising a closed loop vector current controller that incorporates a delay state having a feedback gain is disclosed. Additionally, a method of switching a plurality of block switches that minimizes switching transients is provided. Finally, an article of manufacture containing computer code implementing a modeling and simulation program for modeling a linear motor system is provided.
Claims19
A block switch controller for a linear motor, the linear motor comprising a plurality of motor blocks, a shuttle which is propelled by the magnetic forces generated by a motor current passing through the motor blocks, a plurality of motor block switches selectively passing the motor current through the motor blocks, and a plurality of position sensors determining the position of the shuttle relative to the motor blocks, the controller comprising:
- a. a memory storing a motor current threshold profile, the motor current threshold profile providing for variable current detection thresholds;
- b. a communications interface that enables external communication;
- c. a processing core controlling the plurality of motor block switches, the processing core comparing a measurement of the motor current against the motor current threshold profile stored in memory to determine an effective zero crossing point of the motor current, and
- the processing core controlling the plurality of motor block switches based on the determined effective zero crossing point of the motor current and shuttle position information obtained from the position sensors.
A method of controlling a plurality of motor block switches in a linear motor with a block switch controller, the linear motor comprising a plurality of motor blocks, a motor current, a shuttle which is propelled by the magnetic forces generated when the motor current is passed through the motor blocks, a plurality of motor block switches which selectively pass the motor current through the motor blocks, and a plurality of position sensors which determine the position of the shuttle relative to the motor blocks, the block switch controller executing the following steps:
- a. receiving a measurement of the motor current and position data indicating the position of the shuttle;
- b. retrieving a motor current threshold profile from memory, the motor current threshold profile providing for variable current detection thresholds;
- c. comparing the received motor current measurement with the retrieved motor current threshold profile to determine an effective zero crossing point of the motor current;
- and
- d. controlling the plurality of block switches based on the determined effective zero crossing point of the motor current and the received shuttle position data.
Dependencies are inferred from the claim text.